In post-industrial countries, the average person spends five hours a day on their smartphone – and cancer patients are no exception. As such, it is a powerful tool that can be used to tear down barriers to participation and optimise patient engagement throughout the lifespan of a clinical trial – from enrolment to treatment and completion. Neetu Pundir of Signant Health explores how mobile technology holds a window to a future of clinical trials built on partnership between study organisers and participants.